Scientists discover Australian snubfin and humpback dolphins in a remote Papua New Guinea river system in a find that is so significant the waterway has been designated an Important Marine Mammal Area.

Blood tests are a future possibility and two popular fishing creeks in Darwin should be avoided due to PFAS contamination, Defence says. But it stops short of telling residents not to eat seafood caught there.

A Defence Department meeting in Oakey tells residents there are no health impacts from toxic contamination of local groundwater, but an environmental health expert warns against consuming anything locally grown.

Allegations of illegal land clearing on a north Queensland cattle station have been "dismissed as unfounded" and the property owners were "complying with their obligations under Federal environmental law", the Federal Environment Minister says.

A Sydney court is told Seqwater dam engineers were preoccupied about the "adverse media effects" and "major embarrassment" of unnecessary water releases just weeks before the 2011 Brisbane and Ipswich flood.

Resident Meg Geritz says she was shocked to hear of elevated PFAS levels in Katherine River fish, adding the Defence Department did not seem to understand the impact it could have on the town and its economy.

With the "world's largest" lithium-ion battery officially open in South Australia, many are watching on in anticipation to see what impact it has on the state's electricity market, and whether it could be a gamechanger nationally.

Adani's controversial Carmichael mine is dealt another blow as two of China's major banks say they will not fund the project — a decision that experts say will leave the Indian company relying on public funding.

After resisting offering blood tests to PFAS-affected residents in Katherine for months while making them available to affected people in Queensland and NSW, the Federal Government announces more than $5 million for support services will be made available from Monday.

Environment TV & Videos

Beverley O'Connor talks to Dr Leonid Petrov, a visiting fellow at the Australian National University and a leading North Korea researcher, about US Secretary of State Rex Tillerson's offer to begin talks with North Korea without pre-conditions.